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silverlightsilverlight-4.0wcf-ria-services

How do i write this logic in ria services?


How do i write this logic in ria services? At which place?

The pseudocode for sql is :-

If exists (select recordid from table where recordid = @recordId)
    update the record
else
   insert the record.

The RIA services offer just standard CRUD pattern. Do i have to use Invoke for this? If i use Invoke i will not get the benefits that RIA services offer like change tracking etc. Using Invoke means using RIA service like WCF service.

Thanks in advance :)


Solution

  • There is no reason you cannot extend the boiler plate insert methods RIA generates with your own semantics. The code below I put together as a quick eg for a method to do what you were look for.

    I would suggest that you make sure that this route doesn't cause you issues. I have observed that clientside RIA tends to have a of objects in its contexts after performing operations.

    Hope this helps.

    public void InsertFoo ( Foo foo )
    {
      using ( FooEntities db = new FooEntities() )
      {
        var fooRecord = db.Foos.Where( a => a.fooId == foo.fooId ).SingleOrDefault();
    
        if (fooRecord.Any())
        {
          // Insert
          if ( ( foo.EntityState != EntityState.Detached ) )
            this.ObjectContext.ObjectStateManager.ChangeObjectState( foo, EntityState.Added );
          else
            this.ObjectContext.SystemAccounts.AddObject( foo );
        }
        else
        {
          // Update
          fooRecord.Field = foo.Field;
          db.SaveChanges();
    
          this.ObjectContext.SystemAccounts.AttachAsModified( foo, this.ChangeSet.GetOriginal( foo ) );
        }
      }
    }